Process of discharging



Patented Feb. 21, 1933 PATENT OFFICE JEAN GEORGES PENCHE, OF ROUSSILLON, FRANCE, ASSIGNOB, BY ASSIGNMENTS, TO DU FONT RAYON COMPANY, 015 NEW YORK, N. Y., A CORPORATION OF DELAWARE PROCESS OF DISCHARGING l lo Drawing. Application filed June 25, 1928, Serial No. 288,297, and in Great Britain July 26, 1927.

'This invention relates to the treatment of artificial silk having as its base an organic derivative of cellulose (ester or ether) in the form of filaments, threads, yarns and fabrics containing them. More especially, it relates to a process for discharging a. dye on threads of artificial silk in the form of skeins, webs or fabrics containing them.

lhis invention has for an object a process for discharging dyed threads of artificial 2@ posed shade effects or two-colored ellects respectively.

Another object of this invention is a process for simultaneously discharging and dyeing artificial silk having as its base a cellu- 2 lose derivative (ester or ether).

Other objects will become apparent from the following description and appended claims.

According to this invention, the dyed arti- 0 ficial silk threads or yarns are discharged by means or animal or vegetable charcoal or any other body having high adsorbing properties. These materials may be applied as a suspension in a liquid or in the form of a paste.

1 have found that the discharging action takes place more rapidly and completely when it is carried out at a high temperature and when the contact between the fiber and the adsorbing body is very intimate. Furthermore, l have found that the discharging action of the agent may be in certain cases accelerated by causing the fiber to swell either before or during the discharging process by means of any suitable swelling agent.

-When the discharging composition is applied in the form of a paste, such as animal charcoal mixed with a thickening agent or filler, the process is carried out by steaming.

fil it is followed by rinsing with cold or tepid liquid by means of which the paste is removed. Rinsing at a high temperature as long as the animal charcoal is in contact with the fiber or fabric must be avoided for it might cause a discoloration on areas notidesired. The fiber or fabric is'then washed,

finished, dried and further treated in any The present invention is capable of manyapplications. First, it ailords means for till completely removing a dye on cellulose acetate threads or threads of other cellulose esters or ethers. This may be of great importance. For instance, in the failure of a certain shade, the dyestulls may be removed without affecting in any way the dynamometrical qualities of the threads or their suppleness to the touch.

instead of completely removing the dye from the entire surface of the material treated, it may be discharged from any local or predetermined areas. By this procedure various patterns, such as white discharge efi'ects on a colored background, may be obtained. Materials which have been locally discharged in this manner can be subsequentliy treated to produce ornamental ell'ects by sing with a dye similar to the original dyestud used or with a new dyestud'. When a fabric having locally or predetermined discharged areas is treated with the same coloring matter with which it was originally dyed, superposed shade effects will be obtained.

The regions or areas which have not been subjected to this discharging process will be darker than the regions which have been subjected to the discharging process. if a difi erent dyestufi is used from the original dyestufl', two-colored edects will be obtained. A repetition of the same sequences of operation will produce fabrics having motley e ects.

By regulating the composition of the paste and regulating also the temperature of the operation and its duration, it is possible to obtain more or less complete discharging efiects. It is thus possible by printing the same fabric with difierent pastes, i. e. difierent ingredients and/ or diiierent proportions of the same ingredients, to obtain discharges of different or varying intensity.

The invention also contemplates a simultaneous discharging operation and re-dyeing of the discolored material. To obtain this result it sufiices to add to the paste containing the discharging substance compounds capable of performing the re-dyeing. For example, a. basic coloring matter and a body capable of fixing it on the cellulose acetate fibers, such as sodium resorcinate, may be mixed with the paste. A direct coloring matter susce tible of dyeing cellulose acetate and of a di erent shade from that of the background of the fabric may also be added to the paste containing the adsorbing body if a twotone efi'ect fabric is desired.

A. saponifying agent may even be added to the paste whereby the cellulose acetate fibers are superficially saponified. If desired,

together with this saponifying agent a color-' ing agent or compound adapted to dye the cellulose may be mixed with the paste Whereby the material treated will be dyed. Discharges of difierent or varying intensities may also be secured by treating predetermined areas of threads of organic derivatives of cellulose or fabrics containing the same with a composition including an adsorbing agent and a swelling agent and treating other predetermined areas with a composition in which there is no swelling agent.

In the case of fabrics containing fibers of artificial silk and certain other or foreign fibers, such as natural silk, a discharge efiect may be obtained upon said foreign fibers without the addition of other substances. How ever, a suitable quantity of the discharging agents usually employed for said foreign fibers may be mixed with the paste which contains only the adsorbing agent, whereby the said usual discharging agent will act .more particularly with respect to the other fibers. The charcoal or other adsorbing agent in this process will act more particularly with respect to the artificial silk fibers.

in all applications or the present invention where a printing paste is made use or, all the ingredients which are usually en1- ployed in the industry may be mixed with said paste containing the charcoal; For example, various thickening agents, such as gum arabic, gelose, dextrin, etc, may be added. 1 have found that such products as kaolin,

, fullers earth or infusorial earth give satisfactory results when used in the paste. Kaolin gives especially good results, and compositions including it produce well-defined discharge efiects rapidly. 'lhere may be mixed with the paste such products as glucose or glycerin which enable the paste to retain a certain binding action after the eeann drying operation which takes place immediately after printing.

The dyes for cellulose acetate available to the dyer or printer on which discharge effects may be obtained, according to this invention, have an extremely extensive range of colors.

The present process may be applied to artificial SllkS comprising exclusively cellulose esters or ethers. It is also applicable to materials containing these cellulose derivatives and fillers or adjuvants. It is as effective with bright as with dull silks.

In order to more clearl explain the invention, the following speci c examples are given:

Example I.A. veil of cellulose acetate thread dyed with 1. methylaminoanthraquinone (Duranol red G British Dyestufis Coriporation) is printed with a paste formed wit Grams Annnal charcoal 20 Gum tragacanth 7 5 Vl ater 1,000

The tissue is then steamed for one hour at 95 C. The veil rinsed cold, washed and dried exhibits perfectly white discharge effects at the places treated.

Example 11'.A. satin with a cellulose acetate weft is dyed with 1.4 diaminoanthraquinone (Duranol violet 2B.) and is printed on the satin slde with a paste containing Grams Dimethylaniline m 30 Animal charcoal 15 Gelose 80 Water 1,000 Glycerin (28) it is then steamed for half an hour. After washing, the printed places are discharged in white. The same result may be obtained on the same satin tissue when it has received a dullingtreatment-before the application of the discharge process;

Example lllifilr cellulose acetate tissue with linen cloth cording dyed with an azo dye derived from aniline or its derivatives and dihydroxyquinoline (Dispersol yellow 3G) is printed after dyeing with a paste contaming Grams Animal charcoal 20 Arabic gum 500 Water 500 Ammonium sulpho cyanide 50 acetate web and anatural silk crepe weft is prepared and dyed green with, on the one hand, diaminoanthraquinone (Acetoquinone b'lue-Etablissement Kuhlmann) and 1, aminoanthraquinone (Acetoquinone yellow Etablissement Kuhlmann) for the acetate and, on the other hand, with Malachite green, Colour Index No. 657, for the natural silk. The tissue is printed with a paste containing Grams Animal charcoal Senegal gum 500 Water 500 Glycerin 5O Rhodamine S. C lour Index No. 743.. 80

Sodium resorcinate 10 and dried. After steaming for three-quarters of an hour, rinsing and drying, a tissue is obtained having a red printed pattern on a green background.

Emample V.-A veil made of cellulose acetate thread dyed with diaminoanthrarufiine (Duranol blue) is printed with a paste comprising Animal charcoal 5 grams Ammonium sulphocyanate- 5 grams Kaolin 5 grams Glycerin 5 com. Water 30-50 com.

The paste is dried and the fabric is then steamed for half an hour at 105 C. After washing, the printed portions are discharged in very pure white.

Naturally, any number of printingv rollers can be used, each one coated with a pasteof diiferent composition and obtain in this manner a polychrome impression as complex as may be desired.

It is well understood that the invention is not restricted to the examples given but that it includes all the discharge or discoloring effects obtained by the application of extremely divided adsorbin agents, whatever may be the treatment to w ich the fiber, yarn or tissue has been submitted or to which it will besubmitted after discharge.

I claim:

1. A process for discharging dyed fabrics containing threads of an organic derivative of cellulose which comprises treating said fablrics with a composition containing charcoa 2. A process for discharging dyed fabrics containing threads of an organic derivative of cellulose which comprises treating said fabrics with a composition containing animal charcoal.

3. A process for discharging dyed fabrics containing threads of cellulose acetate which comprises treating said fabrics with a composition containing charcoal.

4. A process for discharging dyed fabrics containing threads of cellulose acetate which containing threads made of cellulose acetate.

which comprises treating said fabrics with a composition containing charcoal and a swelling agent for the cellulose acetate.

6'. A process for dischargingdyed fabricscontainlng threads of an organic derivative of cellulose which comprises applying a com- 0 position containing charcoal and a swelling agent to certain predetermined areas, appl ing a composition containing charcoal wit out a swelling agent to other predetermined areas whereby discharge effects of varying intensities areobtained. I v

7. A process for discharging dyed fabrics containing threads of cellulose acetate which comprises applying a composition containing charcoal and a swelling agent to certain predetermined areas, appl ing a composition containing charcoal wit out a swellin agent to other redetermined areas where y dis-i charge-e ects of varying intensities'are obtained.

8. A process for discharging dyed fabrics containlng threads of an organic derivative of cellulose which com rises treating said fabrics with a compositlon containing charcoal and steaming.

9. A process of discharging dyed fabrics.

containing threads of an organic derivative of cellulose which comprises subjecting said signature to this specification.

JEAN GEORGES- PENCHE. 

